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Home My WebLink AboutNC0020443_SPECULATIVE LIMITS_20050725NPDES DOCUMENT SCANNING COVER SHEET NPDES Permit: NC0020443 Columbia WWTP Document Type: Permit Issuance Wasteload Allocation Authorization to Construct (AtQ Permit Modification Speculative Lrmits- 201 Facilities Plan Instream Assessment (67B) Environmental Assessment (EA) Permit History Document Date: July 25, 2005. This dooumeat is-Priated on rnense PsPer -- igaor40 aay coateat on the re-Werse side Michael F. Easley,"Governor State of North Carolina O0 A rF�QG t, S 7 July 25, 2005 Mr. Carlisle Harrell Town of Columbia P.O. Box 361 Columbia, North Carolina 27925 William G. Ross, Jr., Secretary Department of Environment and Natural Resources Alan W. Klimek, P.E., Director Division of Water Quality Subject: Speculative Effluent Limits Request Town of Columbia NPDES Permit NCO020443 Tyrell County Dear Mr. Harrell: This letter is in response to your request for speculative effluent limits for the proposed expansions of Columbia's wastewater treatment plant from 0.3 MGD to 0.60 MGD. We have reviewed the request and provide the following response. The speculative limits presented here are based on our understanding of the proposal and of present environmental conditions. The Division of Water Quality (DWQ) cannot guarantee that it will issue the Town an NPDES permit to discharge treated wastewater into waters of the State. Nor can we guarantee that the effluent limitations and other requirements included in any permit will be exactly as presented here. Final decisions on these matters will be made only after the Division receives and evaluates a formal permit application for the Town's proposed discharge. Environmental Assessments of New Proiects Please be aware that you will have to evaluate this project for environmental impacts before receiving a modified permit. Anyone proposing to construct new or expanded waste treatment facilities using public funds or public (state) lands must first prepare an environmental assessment (EA) when wastewater flows (1) equal or exceed 0.5 MGD or (2) exceed one-third of the 7Q10 flow of the receiving stream. DWQ will not accept a permit application for a project requiring an environmental assessment until the Division has approved the EA and sent a Finding of No Significant Impact (FONSI) to the state Clearinghouse for review and comment. An Environmental Assessment should contain a clear justification for the proposed project. It should provide an analysis of potential alternatives, including a thorough evaluation of non -discharge alternatives and connection to a regional treatment system. Nondischarge alternatives or alternatives to expansion, such as spray irrigation, water conservation, or inflow and infiltration reduction, are considered to be environmentally preferable to a surface water discharge. In accordance with the North Carolina General Statutes, the preferred alternative must be the practicable waste treatment and disposal alternative with the least adverse impact on the environment. If the EA demonstrates that the project may result in a significant adverse effect on the quality of the environment, you must then prepare an Environmental Impact Statement. North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone (919) 733-5083 Internet: h2o.encstale.mus 512 N. Salisbury St. Raleigh, NC 27604 FAX (919) 733-0719 An Equal ACion cmp^ICy er - 50% Recyclelsnal, Post Consumer Paper o` NrthCarofina Al atma!!y Customer Service 1-877-623-6748 Ms. Carlisle Harrell Town of Columbia Page 2 Speculative Effluent Limits The Division usually performs modeling to determine speculative limits for DO, BOD and Ammonia. The Scuppernong River is tidally influenced at the point of the discharge. The Division doesn't model tidally influenced streams for speculative limits. The approached used for the Town of Columbia was to hold the loads at existing levels to protect the water quality in the river. Past performance data indicates that the discharge is in compliance with the permit limits and no violations of water quality standards have been reported. Based on the available information, tentative limits for the Columbia WWTP at the expanded flow of 0.60 MGD are as follows: t2 BOD, 5-day, 20°C 7.0 mg/L 10.5 Total Suspended Solids 30 mg/L 45 mg/L NH3 as N 2 mg/L 4 mg/L Dissolved Oxygen > 6 mg/L pH 6.8 - 8.5 Fecal Coliform 200 / 100 rnL 400 / 100 mL (geometric mean) Enterococci Bacteria 35 / 100 ml 501 1 100 ml Total Residual Chlorine 28 gg/L Total Nitrogen Monitor Total Phosphorus Monitor BOD5 - The limit for BOD is equivalent to the concentration at the flow of 03 MGD. NNH -N - The limit for NH3-N is equivalent to the concentration at the flow of 0.3 MGD. TSS - The limits for total suspended solids are standard for secondary treatment of municipal wastewater. D.O. - The D.O. limit is a water quality based limit to protect the receiving stream. Fecal Coliform, PH - The limits for fecal coliform bacteria and pH are derived to protect water quality in the receiving stream. Total Residual Chlorine (TRQ - Facilities that use chlorine disinfection receive a total chlorine limit to protect against chlorine toxicity in the receiving stream. Enterococci Bacteria — EPA promulgated enterococci criteria for coastal marine waters on December 2004. All facilities discharging to SC, SB and SA waters are subject to the limits. With the increase in flow above 0.5 MGD and the nutrient reduction requirements, the classification of the facility would change to Class III, and the requirement for certified operators changes accordingly. Also note that the limits presented above were based on the information presented in the speculative limits request. A complete evaluation of these limits and monitoring frequencies in addition to monitoring requirements for metals and other toxicants will be addressed upon receipt of a formal NPDES permit application. -11 Ms. Carlisle Harrell Y Town of Columbia Page 3 I trust this response offers sufficient guidance for the Town's proposed treatment plant expansion. If you have any additional questions about these limits, feel free to contact Teresa Rodriguez at (919) 733-5083 ext. 553. Sincerely, A,- 44L Gil Vinzani, P.E. EAST NPDES Unit Supervisor cc: Central Piles Washington Regional Office EAST NPDES Unit files F. Tyndall Lewis, P.E. — McDavid Associates, Inc. P.O. Box 1776 Goldsboro, North Carolina 27533 W5charr ,(,) SGp zrnoriC, ei O 3U o%nk� PJ --� — - 5�I(bafoad�a� CJ- 4 rn�JL.. )0 161d — � mil L J u -4k vh Vic. 906 rnu-ApUQm CPoA- 2 n(64D- 4.5 C80b= 151C2= 3o rn5JL nPcob = 4K4,S — 12 9 f L U 3o+n I L LxevD �gr- o.cv µGA a 04, 6L,;o L 1 r jAj6gv im r-)OK),4vrlY-f- a0o3 I P o d �I� UD -- cs� Fla) 3 - y 13, r &f 26 U 5 10 SFr INC. - McDAVIDAssocuTEs, INC. Engineers • Planners • Land Surveyors CORPORATE OFFICE (252) 753-2139 • Fax (252) 753-7220 120 N. Main Street • P.O. Drawer 49 Farmville, NC 27828 March 2, 2005 Mr. David Goodrich Point Source Branch NC Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 SUBJECT: Request for Speculative Limits Columbia Wastewater Treatment Plant Tyrrell County, NC Dear Mr. Goodrich: GOLDSBORO OFFICE (919) 736-7630 • Fax (919) 735-7351 109 E. Walnut Street • P.O. Box 1776 Goldsboro, NC 27533 The Town of Columbia operates a .3 MGD wastewater treatment plant that discharges to the Scuppernong River (NPDES Permit NC 0020443). The Town is planning to increase the plant's capacity to .6 MGD in the near future. Please provide speculative limits for an increase in discharge to .6 MGD. The limits will be used in the comparison of various alternatives to increase the plant's capacity. A copy of a USGS map (Columbia West) is attached to illustrate the location of the existing discharge. If you have any questions, please do not hesitate to call me. Sincerely, McDAVID ASSOCIATES, INC. F. Tyndall Lewis, PE Goldsboro Office FTL: Attachment cc: Town of Columbia \\G-PC 1 \D805\FTL\2005\CLSLW WTP. LTR COLUMBIA-DWQ-SPECULATIVE-LIMITS-W WTP.LTR 050302 Td � g�q f COT B oil � _. 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